Tokyo Butei High School is a special school where armed detectives—"Butei"—are trained to use weapons. Kinji Tōyama is a second year student who has a special ability, but he keeps it a secret to maintain an ordinary, peaceful life. However, when he gets caught in a bombing on the way to school, he encounters Aria H. Kanzaki, the most powerful S-Rank Butei student in Assault Studies.
With beautiful assistant Sahoto Ashisu aside, mangaka (and cherry boy) Yūki Aito can hardly concentrate on his works, forcing his managing editior Mihari Otosuna to push him (physically) meeting the deadline. With new busty but ditsy Rinna Fuwa and skilled but money-loving Sena Kuroi joining the assistant pool, Yūki's life is more like a harem than a manga studio.